Although most of the foreclosure properties listed on RealtyTrac are single family homes, any type of property can fall into foreclosure. That includes all kinds of commercial property and unfinished developments -- like one in San Antonio that sold at foreclosure auction Tuesday for $4.77 million, according to the San Antonio Express-News:

A creditor foreclosed Tuesday on a half-completed project on Broadway near the Interstate 35-Interstate 37 interchange, clearing the way for progress on its hulking concrete building shells.

Villaje del Rio was conceived by Geis as a mixed-used development of apartments and office and retail space.

This property was originally listed on RealtyTrac in May with an auction date in June. It was posted again on RealtyTrac in July with its rescheduled auction date of Aug. 1. It may have been a good opportunity for an investor or group of investors interested in developing in San Antonio's downtown area.

Another property with foreclosure documents filed mid development is located in Boynton Beach, Fla., and is described by the Palm Beach Post as "an appealing site for retail."

A preschool, a one-story office building and a drugstore all are nearby, and hundreds of condos and single-family homes ring the area. It's why mom-and-pop tenants such as Marc's Bagels and a nail salon are setting up shop ...

When most people think of investing in foreclosures, they think of single family homes and dealing with individual homeowners in default. But as the above stories shows, diverse investment opportunities are available when it comes to the foreclosure market.